Correction
In the article “A Double-Blind Randomized Controlled Trial of N-Acetylcysteine in Cannabis-Dependent Adolescents,” by Kevin M. Gray, M.D., et al. (Am J Psychiatry Original article: 2012; 169:805–812), Figure 3 was originally published online (in “AJP in Advance”) with an incorrect scale for the y-axis. The figure appears as intended for the article's appearance in the August 2012 issue and in the online version posted as part of that issue.